pests

Spiders And Pest Control | Earth Wise

April 5, 2023 By EarthWise Leave a Comment

Climate change facilitates the spread of invasive pest species by expanding their habitable environment ranges. In conventional agriculture, farmers depend on chemical pesticides to control agricultural pests. But 99% of all synthetic chemicals, including pesticides, are made from fossil fuels, and turning petrochemicals into pesticides requires massive amounts of energy. These chemical pesticides also pollute the air and water, and destroy biodiversity by killing many non-target species as well.

According to new research led by scientists from the University of Portsmouth in the U.K., groups of spiders could be used as an environmentally-friendly way to protect crops against agricultural pests. The study, which was recently published in the journal Insects, suggests that web-building groups of spiders can be used to control populations of the tomato leafminer moth, a devastating pest of commercially important crops like tomatoes and potatoes.

The research team explored the use of tropical tent spiders for this pest control. They are found in colonies around the world, and their range overlaps with regions of moth infestations, including Mediterranean Europe, Africa, Asia, and the Middle East.

In lab settings, different types of prey were introduced to colonies of spiders of varying body sizes. The research team found that the larger spiders built larger webs and caught more prey, including tomato leafminer moths and fruit flies.

Tropical tent spiders could be an effective and climate-friendly way to control flying insect pests. However, more research is needed to ensure that these spiders don’t negatively impact crop pollination by also catching pollinators.

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Using spiders as environmentally-friendly pest control

Photo, posted June 10, 2018, courtesy of Lies Van Rompaey via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

A Vaccine For Bees | Earth Wise

February 27, 2023 By EarthWise Leave a Comment

The US has seen annual reductions in honey bee colonies since 2006. According to the USDA, there are many factors that have contributed to the decline. These include parasites, pests, insecticides, disease, and a phenomenon called Colony Collapse Disorder in which worker bees abandon a hive and leave behind the queen.

One of major threats to bee colonies is American foulbrood disease, which is a bacterial condition that attacks bee larvae. It is highly contagious and has no cure. Until now, the only treatment method required burning the colony of infected bees along with the hives and equipment and treating nearby bee colonies with antibiotics.

Recently, the USDA has approved a conditional license for the world’s first vaccine for honey bees. The vaccine contains inactive bacteria of the type that causes American foulbrood disease.

The vaccine is incorporated into the royal jelly fed by worker bees to the queen bee. The queen ingests the feed and keeps some of vaccine in her ovaries. This gives bee larvae immunity to the disease as they hatch and thereby reduces death from the illness.

According to the California State Beekeepers Association, the new vaccine could be a major breakthrough for protecting bees. Preventing the infection in hives could avoid costly, destructive measures and allow the beekeepers to focus on other important elements of keeping bees healthy.

Bees as pollinators play a critical role in many ecosystems. For humankind, pollinators such as bees, birds, and bats are responsible for about a third of the world’s crop production.

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US approves world’s first vaccine for declining honey bees

Photo, posted June 6, 2022, courtesy of Bernd Thaller via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Declining Flying Insects | Earth Wise

June 30, 2022 By EarthWise Leave a Comment

In recent years, there has been increasing awareness of the global decline in insect abundance. A recently published survey of the abundance of flying insects in the UK has revealed very troubling results.

The Kent Wildlife Trust and Buglife – two UK-based conservation groups – compared the number of dead insects on vehicles in 2004 and 2021. In this Bugs Matter Citizen Science Survey, the data was collected by roughly 20,000 ordinary citizens using a smartphone app.

The results were that the number of flying insects in Britain dropped nearly 60% over that time period. The insects declined most in England and Wales, with drops of 65% and 55%, respectively.

It is possible that 2004 was a particularly good year for British insects and 2021 an especially bad one, but the findings of this study are consistent with other research around the world showing an alarming decline in insects. A series of studies in 2019 found that the global mass of insects is shrinking by 2.5% a year and that insects are going extinct eight times faster than reptiles, birds, or mammals.

Insects face multiple overlapping threats including the destruction of wild habitats for farming, urbanization, pesticides, and light pollution. On top of these things is climate change which is disrupting ecosystems in multiple ways.

Insects play a vital role in pollinating crops, consuming organic waste, killing pests, and as essential parts of multiple ecosystems. Severe insect declines can potentially have dire global ecological and economic consequences.

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Flying Insects Have Declined by 60 Percent in the U.K., Survey Finds

Insect decline in the Anthropocene: Death by a thousand cuts

Photo, posted May 6, 2007, courtesy of Richard Giddins via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Managing Pests With Cover Crops | Earth Wise

May 18, 2022 By EarthWise Leave a Comment

The use of pesticides in global agriculture brings with it many problems including the killing of non-target, beneficial species as well as reversing pest-management gains from the use of conservation agriculture methods.

In a newly published study by researchers at Penn State University, the use of plant cover, such as cover crops, was shown to potentially be more effective at reducing pest density and crop damage than the application of insecticides without the downsides. Cover crops reduce insect pest outbreaks by increasing pest predator abundance.

Cover crops are plantings that are primarily used to slow erosion, improve soil health, enhance water availability, smother weeds, and help control pests and diseases. Typical cover crops include mustard, alfalfa, rye, clovers, buckwheat, and winter peas. Most cover crops are fairly inexpensive to plant.

Plant cover can provide habitat for populations of natural enemies of pests. Winter cover crops can harbor pest predator populations outside of the growing season of the cash crop. When the cover crop is killed off to allow the growth of the cash crop, residues of the cover crop remain on the soil during the growing season, so they still enhance the habitat for pest predators.

Conservation agriculture includes methods like cover crops, no-till planting, and crop rotation. The use of cover crops constitutes a form of preventive pest management that is an alternative to planting seeds treated with systemic insecticides to control early-season pests. There is also the possibility for integrated pest managements, which is an approach in which insecticides are applied but only when pest numbers exceed economic thresholds despite the use of nonchemical tactics.

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Cover crops more effective than insecticides for managing pests, study suggests

Photo, posted August 8, 2011, courtesy of USDA NRCS Montana via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Coffee And Climate Change | Earth Wise

December 20, 2021 By EarthWise Leave a Comment

Over 2.25 billion cups of coffee are consumed in the world each day. Americans spend $80 billion dollars a year on coffee. Coffee in grown across 12.5 million largely smallholder farms in more than 50 countries. In other words, coffee is a big deal.

Like many things, coffee is subject to the effects of climate change. Many coffee-producing regions are experiencing changing climate conditions, which don’t only affect the yield and sustainability of the crop but have an impact on taste, aroma, and even dietary quality. Coffee drinkers care very much about these things.

New research at Tufts University and Montana State University looked at how coffee quality can be affected by shifts in environmental factors associated with climate change. The researchers looked at the effects of 10 prevalent environmental factors and management conditions associated with climate change and climate adaptation.

The most consistent trends were that farms at higher altitudes were associated with better coffee flavor and aroma, while too much light exposure was associated with a decrease in coffee quality. They also found that coffee quality is also susceptible to changes due to water stress and increases in temperature and carbon dioxide levels.

They evaluated current efforts to mitigate these effects, including shade management, selection of climate resistant coffee plants and pest management. The hope is that if we can understand the science of the changes to the environment, it will help farmers and other stakeholders to better manage coffee production in the face of increasing challenges. It will take a concerted effort to maintain coffee quality as the climate continues to change.

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Coffee and the Effects of Climate Change

Photo, posted May 22, 2009, courtesy of Olle Svensson via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

How Quickly Can The Planet Recover? | Earth Wise

December 6, 2021 By EarthWise Leave a Comment

Climate change refers to long-term shifts in temperatures and weather patterns. Historically, these shifts were natural. But since the Industrial Revolution, scientists have found that the main driver of climate change has been human activities, primarily by adding significant amounts of greenhouse gases into the atmosphere through the burning of fossil fuels.

Today, climate change is destabilizing Earth’s temperature equilibrium and is having a widespread impact on humans, animals, and the environment. Some of the consequences of anthropogenic climate change include warmer air and ocean temperatures, shrinking glaciers, increasing spread of pests and pathogens, declining biodiversity, and more intense and frequent extreme weather events.

But how quickly can the climate recover from the warming caused by an increase in carbon dioxide in the atmosphere?

Researchers from Johannes Gutenberg-University Mainz in Germany looked into this question by investigating the significant rise in global temperatures that took place 56 million years ago. Likely triggered by a volcanic eruption, the increase of between 5 and 8 degrees Celsius was the fastest natural period of global warming that has impacted the climate.

Because higher temperatures cause rocks to weather faster, the research team decided to analyze the weathering processes that occurred during the warming event 56 million years ago. Their findings, which were recently published in the Journal Science Advances, indicate that the climate took between 20,000 and 50,000 years to stabilize following the rise in global temperatures.

Climate change is not some distant problem. It is happening now and it poses a serious threat to all forms of life. We need to address the problem with more urgency.

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How quickly does the climate recover?

Photo, posted August 27, 2017, courtesy of Lt. Zachary West (100th MPAD) / Texas Military Department via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Harnessing The Smell Of Fear | Earth Wise

September 28, 2021 By EarthWise Leave a Comment

Plant-eating insects present a major problem for farmers and home gardeners. Aphids, for example, are a highly destructive pest to many crops. Their large numbers and ability to transmit plant pathogens make them a persistent problem for growers.

Pesticides are chemical substances that are commonly used to prevent, destroy, repel or mitigate pests. They include insecticides for insects, rodenticides for rodents, herbicides for weeds, and fungicides for microorganisms. According to the U.S. Geological Survey, approximately one billion pounds of these chemicals are used in the United States every year.

But pesticides can also contaminate soil, water, and other vegetation, as well as kill many non-target species. Exposure to these chemicals is dangerous for human health.

According to a new study, researchers from Pennsylvania State University have developed a way to bottle the “smell of fear” produced by predators in order to repel and disrupt pests naturally without the need for these harsh substances. The researchers recently presented their findings at the American Chemical Society meeting.

Aphids happen to be a favorite food of ladybugs. Aphids and other herbivorous insects will steer clear of fields and gardens if they smell predators nearby. The researchers identified and extracted the volatile odor profile from ladybugs. The researchers used the compounds to create a special odor blend that can be used in an essential oil diffuser to spread the scent across a garden or field.

The research team plans to conduct field tests to see if the effects outside are similar to what was observed in the lab. A natural and effective pest repellent would be a big win for people and the planet.

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Protecting gardens and crops from insects using the ‘smell of fear’

Protecting gardens and crops from insects using the ‘smell of fear’ (YouTube)

Photo, posted May 10, 2011, courtesy of DM via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

The Cost Of Invasive Species | Earth Wise

May 7, 2021 By EarthWise Leave a Comment

A new study published in Nature has tried for the first time to put a price tag on the impact of invasive species. Researchers have been studying the effects of invasive species for decades, but it is a problem that has not really captured the attention of the public and policy makers.

According to the research by scientists at the French National Museum of Natural History, from 1970 to 2017, invasive species have cost the global economy at least $1.28 trillion dollars in damages and efforts to control them.

The team screened over 19,000 published papers, ultimately analyzing nearly 2,000 that detailed costs of various invasions at particular times. Annual costs roughly doubled every six years, reaching a yearly bill of $162 billion in 2017.

The five costliest invasive species are Aedes mosquitos, rats, cats, termites, and fire ants, collectively accounting for a quarter of the global damage.

Asian tiger mosquitos and yellow fever mosquitos alone accounted for $149 billion in damage to public health as they spread from country to country. Rats hitchhike on human boats and drive native species to extinction on islands around the world. Cats inflict damage primarily by their impact on native biodiversity. By some estimates, they kill a billion birds each year in the US alone. Termites, as they spread across the globe, wreak havoc on all sorts of infrastructure. Fire ants can feed on a variety of seedlings, from citrus to soybeans, reduce the size of grazing lands for livestock and bite and sting farm animals and humans.

The study shows invasive species are a massive problem that is getting worse.

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Invasive Species Cost Billions of Dollars in Damages Annually, Researchers Find

Photo, posted March 29, 2012, courtesy of Aleksey Gnilenkov via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Tropical Species Moving North | Earth Wise

April 19, 2021 By EarthWise Leave a Comment

Climate change is leading to warmer winter weather throughout the southern U.S., providing opportunities for many tropical plants and animals to move north. A new study by scientists at UC Berkeley looked at the changing distribution of tropical species driven by the warming climate.

Some species are appreciated in their new locations, such as sea turtles and the Florida manatee, which are gradually moving northward along the Atlantic Coast. Others, like the invasive Burmese python are not so welcome. That goes double for many insects, such as the mosquitoes that carry diseases like the West Nile virus, Zika, dengue, and yellow fever, as well as beetles that destroy native trees.

The transition zone, northward of which experiences freezes every winter, has always been a barrier to species native to more temperate places. For most organisms in such places, if they freeze, they die. Cold snaps like the recent one in Texas usually don’t happen for decades and are now likely to be less and less frequent. In the meantime, tropical species can get more and more of a foothold and maybe even develop populations that can tolerate more cold extremes in the future.

The warming climate is leading many plant species to expand their ranges, in some cases pushing out native species. The general story is that the species that do really well are the more generalist species whose host plants or food sources are quite varied or widely distributed and can tolerate a wide range of conditions. By definition, they tend to be the pest species.

We need to prepare for widespread shifts in the distribution of biodiversity as climate, including winter climate, changes.

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Tropical species are moving northward as winters warm

Photo, posted May 7, 2010, courtesy of Jim Reid / USFWS via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Not Enough Buzz For Bees | Earth Wise

February 11, 2021 By EarthWise Leave a Comment

The dramatic worldwide decline in bees and other pollinating insects represents a serious threat to the global food supply, but it isn’t really getting much attention in the mainstream news. Close to 75% of the world’s crops for human consumption depend, at least in part, on pollinators for sustained production, yield, and quality.

A new study by researchers at the University of Illinois Urbana-Champaign looked at nearly 25 million news items from six prominent sources, including The New York Times, The Washington Post, the Associated Press, as well as three overseas English-language news services. The study found “vanishingly low levels of attention to pollinator population topics”, even compared with what many people consider to be the limited coverage of climate change.

The study made use of the Global News Index, which is a unique database of millions of news items from thousands of global sources published over decades. It may be the largest academic study of the evolving nature of news coverage ever performed.

Even though the entomological community is highly focused on the impending pollinator crisis, the public is not paying much attention. It is not even indifference; it is just that people don’t even know about it.

The majority of studies on pollinator decline have been done in Europe and North America, which means we don’t even know how serious the problem is given that most insect biodiversity is in the tropics.

Public awareness is important because individuals can make a difference by their decisions about what flowers to plant in their gardens, which weeds to tolerate in their yards, and how to manage insect pests.

The loss of pollinators is a very serious problem, and it is not likely to get enough attention if people don’t know about it.

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Pollinators not getting the ‘buzz’ they need in news coverage

Photo, posted December 28, 2006, courtesy of Alpha via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Essential Oils And Organic Crops | Earth Wise

November 6, 2020 By EarthWise Leave a Comment

Essential oils are concentrated liquids extracted from plants. They are called “essential” in the sense that they contain the essence of the fragrance that is characteristic of the plant. Essential does not mean indispensable or usable by the human body. But despite that fact, essential oils have been used in folk medicine throughout history.

In recent times, essential oils have frequently been used in aromatherapy. Generally speaking, medicinal uses of essential oils are controversial, and, in some cases, they have even been demonstrated to be dangerous.

Research has shown that essential oils have potential as natural pesticides. Recently, the USDA has funded research into the use of essential oils to battle pests and diseases of organic crops.

U.S. organic food sales topped $50 billion in 2018 and fruits, vegetables, and other specialty crops combined make up more than a third of organic sales. In order to meet consumer demand, farmers need ways to battle pests and diseases that often accompany organic crop growth.

A four-year project at the University of Hawaii at Manoa is entitled “Plant Safety, Horticultural Benefits, and Disease Efficacy of Essential Oils for Use in Organically Grown Fruit Crops: From the Farm to the Consumer.” The researchers will work with certified organic producers in Hawaii, Florida, South Carolina, Georgia, and California to evaluate the effectiveness of plant essential oils on major fruit pathogens such as avocado scab, anthracnose fungal disease, and powdery mildew on targeted tropical and temperate fruit crops such as avocado, mango, blueberry, and peach.

The goal is increase orchard productivity of the expanding organic fruit industry.

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Essential oils could keep pests, disease from organic crops

Photo, posted January 6, 2015, courtesy of Abi Porter via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Tracking Locust Swarms | Earth Wise

June 12, 2020 By EarthWise Leave a Comment

Plagues of locusts have been reported since the times of the Egyptian pharaohs. In recent history, there have been desert locust plagues during multiple decades of the 20th century. Since January, a very large population of locusts gathered in Kenya and has destroyed over 2,000 square miles of pasture and crop land. Swarms have since reached portions of Ethiopia, Somalia, Uganda, and South Sudan. Apart from East Africa, there are locust swarms in Yemen and other Middle East countries and in Pakistan as well. The current situation continues to represent an unprecedented threat to food security and livelihoods in East Africa. Locust swarms can range in size from less than half a square mile to hundreds of square miles, each containing 20 to 40 million locusts.

The National Oceanic and Atmospheric Administration uses a powerful air quality model to track the movement and deposition of pollution from wildfires, volcanoes and industrial accidents. Called the HYSPLIT dispersion model, it has now been refined for the purpose of tracking swarms of locusts.

Because desert locusts are passive fliers that drift with the wind, the model’s high-quality data on wind speed and direction can lead to accurate predictions of where the locusts will go and when.

NOAA is working with the United Nations Food and Agriculture Organization – the FAO. The new web application based on HYSPLIT is being used by the FAO to issue forecasts and warnings to affected countries about forthcoming waves of locust swarms. Such forecasts enable local officials to conduct aerial spraying to reduce the impact of desert locusts which can destroy grains, grasses and other greens that are life-sustaining foods for entire regions.

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NOAA teams with United Nations to create locust-tracking application

Photo, posted November 20, 2004, courtesy of Niv Singer via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Controlling Malaria Without Chemicals

August 28, 2019 By EarthWise Leave a Comment

Nearly half of the world’s population lives in areas vulnerable to malaria. The disease kills roughly 450,000 people each year, most of them children and pregnant women. Malaria is spread by Anopheles mosquitoes and, over time, the mosquitoes have been developing resistance to the chemical insecticides that are used to control them. In addition, there is great concern about the toxic side effects of the chemicals used on the mosquitoes.

About 30 years ago, scientists identified a type of bacteria that kills Anopheles, but the mechanism was not understood. As a result, the bacteria could not be replicated or used as an alternative to chemical insecticides.

But now, an international research team, headed by researchers at UC Riverside, has identified the neurotoxin produced by the bacteria and has determined how it kills Anopheles. The work is described in a paper published in Nature Communications.

It took the team 10 years to achieve a breakthrough in understanding the bacteria. Modern gene sequencing techniques were the key.

While many neurotoxins target vertebrates and are highly toxic to humans, the neurotoxin that kills Anopheles mosquitoes does not affect humans, vertebrates, fish, or even other insects. Known as PMP1, the substance is not even toxic to mice when given by direct injection.

The team has applied for a patent on this discovery and hopes to find partners to help them develop the bacteria-based insecticide.

There is a high likelihood that PMP1 actually evolved to kill the Anopheles mosquito. This finding opens the door to new avenues of research into other environmentally friendly insecticides that would be targeted at other disease-spreading pests.

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Controlling deadly malaria without chemicals

Photo, posted June 9, 2018, courtesy of Mario Yardanov via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Exotic Pets Can Become Problems

August 26, 2019 By EarthWise Leave a Comment

Each year, millions of exotic animals are sold as pets around the world. The term “exotic” lacks a set definition but is generally used to refer to an animal that’s wild or more unusual than standard pets, like cats and dogs.

The exotic pet trade is a multi-billion dollar industry, involving tens of millions of individual animals from thousands of species, including reptiles, amphibians, fish, birds, and mammals.

Some of the exotic pet trade is legal, but a lot of it isn’t. Many animals are illegally captured from the wild to meet the global demand for exotic pets.

People often purchase exotic animals without completely understanding the consequences. Some exotic pets, for example, can live nearly twice as long as the average dog. Caring for exotic pets can be both expensive and risky, since they are largely undomesticated (and therefore can have unpredictable behavior).

As a result, it’s not uncommon for owners to release exotic pets intentionally. When this happens, the consequences can be catastrophic. Sometimes the animal dies from starvation or predation, but in other instances, the animal proliferates and becomes an invasive species.

Invasive species are the second largest driver of biodiversity loss worldwide, and they cost the U.S. $120 billion a year.

According to an academic review recently published in the journal Frontiers in Ecology and the Environment, the exotic pet trade is one of the primary causes of the spread of invasive species and has fueled the establishment of hundreds of them. Tegus, Burmese pythons, and red lionfish are examples of pets-turned-pests.

The best way to combat this trend is through education, detection, and rapid response.

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Why you should never release exotic pets into the wild

Photo, posted September 19, 2010, courtesy of Mike Baird via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Shipping And Invasive Species

May 7, 2019 By EarthWise Leave a Comment

The increasing numbers of invasive species around the world are a major driver of biodiversity change and cause billions of dollars in economic damages annually. Climate change is a major factor in the spread of invasive species, but a new study by McGill University suggests that global shipping growth will far outweigh climate change in the spread of non-indigenous pests to new environments in the coming decades.

One of the most significant ways in which the disparate regions of the world are interconnected is via transportation networks. The global shipping network is the primary means by which materials and goods are moved worldwide, accounting for over 80% of world trade. And for this reason, the global shipping network is responsible for much of the introduction of non-indigenous species across the planet.

Living organisms are often transported through ballast water, which is taken up to stabilize cargo vessels. Other species are transported by biofouling, whereby they attach to the hulls of ships. Taken together, these two pathways account for anywhere between 60 and 90% of marine bioinvasions. (Terrestrial invaders are generally moved as a byproduct of shipping, for example by infesting wood packaging material).

The McGill study looked at trends in global shipping and how socioeconomic factors are driving change. For example, China’s share of global container throughput has gone from 1.4% in 1990 to 20.1% in 2013. So, the distribution and patterns of shipping have been changing dramatically and with it the spread of non-indigenous species.

Awareness of this issue is increasing. For example, there have been policy initiatives such as the International Ballast Water Management Convention that is an effort to control bio-invasions through measures such as ballast exchange. We need to take measures to limit the unintentional spread of species.

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